Scaffold and winding apparatus

ABSTRACT

An apparatus for wrapping prestressing steel wire around the outer surface of a concrete tank is shown. The apparatus includes a plurality of vertical steel bracing beams which are attached to the inside surface of the concrete wall. A guide rail is attached to those bracing beams. A scaffold is mounted on a movable rubber wheel which is positioned to move along the upper surface of the concrete wall. The scaffold is movably braced by means of a trolley wheel or the like which is retained in the guide rail attached to the bracing beams. A second wheel is mounted in the scaffold to contact and roll around the upper side surfaces of the tank wall. The apparatus for winding prestressing wire around the exterior surface of the wall is supported on cables wound on a mounted winch on a platform on the scaffold. With the apparatus of the invention, the winding apparatus can be moved continuously around and up and down a concrete wall to be prestressed.

United States Patent 1191 Bush- I Dec. 10, 1974 SCAFFOLD AND WINDING APPARATUS Primary Examiner-Billy S. Taylor [75] Inventor: Billy Ross Bush, West Babylon, Attorney, Agent, or Firm-Curtis, Morris & Safiord [7 3] Assignee: The Preload Company, Inc., Garden [57] ABSTRACT City, An apparatus for wrapping prestressing steel wire [22] Filed: No 14, 1972 around the outer surface of a concrete tank is shown. The apparatus includes a plurality of vertical steel PP 306,201 bracing beams which are attached to the inside surface of the concrete wall. A guide rail is attached to 52 us. (:1. 242/7.21, 52/224 ihss hissing bsaihs- A ssafishi is minted a 51 Int. (:1 B21f 17/00 shis mhhsi whssi which is Psiiihsd is sishg 581 Field of Search 242/721, 7.22, 7.23, 7.02; the "PPer surface ihs The is 182/37 X 36, 187 X; 52/224 movably braced by means of a trolley wheel or the like which is retained in the guide rail attached to the [56] References Cited briziztinlg1 beams. A 'sesonilil wheeldishmounted in the sc 0 to contact an ro aroun t e up er side sur- UNITED STATES PATENTS 4 faces of the tank wall. The apparatus for rinding prel,929,325 10/l933 Masterson 182/36 X stressing i around the exterior s f of the wall is i ggi ggg 5x32; supported on cables wound on a mounted winch on a 3 245 355 4/1966 Cousins et ;i:::.......:: 182/36 tux platfhhm f whh the apparatus the 3:687:380 8/1972 Magers 242 7.21 vemwn the winding apparatus can be mved minim ously around and up and down a concrete wall to be FOREIGN PATENTS OR APPLICATIONS prestressecL 254,486 5/1967 Austria 182/37 2 Claims, 5 Drawing Figures It is known in the art to wrap continuous strands of wire around the external surface of a cylindrical or elliptical concrete tank. The prestressing wire is typically wrapped in discontinuous bands or more frequently as continuous, helical windings. The wire is under tension and places the concrete wall in prestress compression so that the wall, in its service condition, as for example in containment of liquids, will not fail in tension. Patents which disclose apparatus and methods for winding prestressing wire around the exteriors of tanks include US. Pat. Nos. 2,370,780; 2,364,696 and 2,385,796 to J. N. Crom, and U.S. Pat. No. 3,377,757 to L. Magers, Jr.

In recent years the size of concrete tanks for various services has been increased and it is economically imperative to efficiently construct and prestress the concrete tanks with a minimum of equipment and work effort. The prior art apparatus for prestressing has certain salient disadvantages. The supporting apparatus is generally quite complicated requiring cables running to the center of the tank and relatively intricate supporting and bracing apparatus for the wire winding machines. A particular disadvantage encountered when using the apparatus of J. M. Crom, for example, is that only a single concentric wall can be wrapped with prestressing wire at one time. Still another disadvantage of the prior art systems is where the apparatus is suspended from a center point or center points on a tank structure; the support apparatus tends to interfere with any scaffolding or apparatus which might be used for performing useful work on the interior surface of the tank wall. A disadvantage where systems employing cranes are used is that these tend to be relatively heavy to support the moments encountered in supporting the prestressing apparatus and are therefore heavy to bring to and from the work site.

lt is thus the broad and primary object of this invention to provide an apparatus for performing work on either the interior or exterior surface of a vertical tank wall.

It is a further and more specific object of this invention to provide an apparatus for wrapping prestressing steel wire around the outer surface of a concrete tank having a continuous vertical wall.

It is still a further and related object of this invention to provide a scaffolding apparatus for supporting a work station for use on the interior or exterior walls of a tank which is simple and efficient to use and does not have the multiple disadvantages of prior art apparatus.

It is a further and specific object of this invention tp provide a scaffolding apparatus for supporting a wire wrapping apparatus for use in wrapping the exterior of a concrete tank, which is not supported at the center of the tank which is relatively light weight and simple to use.

It is still a further object of this invention to provide a scaffolding and support means for a wire wrapping apparatus, which do not preclude the simultaneous prestressing of the exterior surfaces of several concentric concrete walls or the conduct of work on the interior of these walls.

It is still a further object of this invention to provide an apparatus which can be used to wrap prestressing wire around non-circular walls, i.e. walls having a surface which conforms to a surface of revolution.

These and other objects of this invention are broadly achieved in an apparatus for performing work on the side surface of a vertical wall which includes a rigid brace means attached to the wall and extending above it on the side thereof where work is not to be performed. The braces have a continuous guide means attached thereto which is positioned essentially parallel to the course of the wall. A scaffold, which is movable along the top surface of the wall, is provided. It includes a roller or other suitable means movably retained in the guide means attached to the braces. The scaffold further includes a support platform for supporting a vertically suspended work station. The work station may include further scaffolding or may include a prestressing wire wrapping apparatus.

.Bss rablx the brass. U!? n lusis a plura ty o vertical beams which are bolted to the top of the wall andwhich extend vertically above it. The guide rail may be an I beam or the like attached to the exterior or interior faces of the beams as the case may be. The scaffold part of the apparatus includes a wheel which is mounted essentially vertically on the axle in the scaffold structure. The wheel is positioned to move along the top of the wall and supports essentially all of the vertical load of the apparatus. A second, stabilizing wheel is mounted essentially horizontally on another axle in the scaffold and moves along the upper side surface of the wall where work is to be performed. The

scaffold also includes a winch for raising and lowering the work station. The work station itself may be a semienclosed cage having a variety of work apparatus enclosed therein such as a wire wrapping apparatus. Desirably the work station includes wheels in contact with the wall surface to facilitate movement of it therealong.

In the preferred embodiment the apparatus is adapted for wrapping prestressing steel wire around the outer surface of the concrete tank. The concrete tank typically will have an endless vertical wall which defines a surface of revolution as, for example, a cylinder or ellipse. A plurality of vertical steel bracing beams are attached to the upper part of the inside surface of the concrete wall preferably by bolting. These beams extend above the wall and have a guide rail, preferably an l beam, attached continuously to their outer faces and positioned essentially parallel to the course of the wall. The I beam comprises a guide rail for movably retaining a trolley wheel attached to the scaffold as is further described below. A steel scaffold, comprised of frame members, is provided and it has self-propelling means for moving it along the top of the wall. The scaffold may include any suitable number of structural frame members and includes a member extending towards the vertical bracing beams and having trolley wheels or the like mounted thereon. The trolley wheels are retained in the guide rails. The scaffold is supported vertically on the rubber wheel which is mounted on an axle mounting in the scaffold. The wheel is in turn positioned to roll along the top of the wall and desirably it has a rubber tire on it. A suitable motor drive is provided to propel the wheel and scaffold along the top of the wall. A second wheel or plurality of wheels are mounted in the scaffold in a horizontal orientation in a suitable axle mounting. The second wheel is positioned against the top exterior surface of the wall so that it rolls along that surface providing an additional point of moving contact for the scaffold and the wall. The scaffold includes a support platform having a winch mounted thereon for raising and lowering the work station which may contain a conventional winding apparatus for wrapping prestressing wire around the exterior of the tank wall. Desirably the work station is raised and lowered from the platform by means of a cable which is wound around the winch on the support platform and which passes from that winch downwardly through a block or blocks associated with the work station and then upwardly to a position on the scaffold located below the work station. A safety cable may be wrapped endlessly around the upper part of the wall passing through a suitable system of pulleys on the work station to both remove slack from the safety cable and to provide a failsafe support system for the entire apparatus.

I IN THE DRAWINGS FIG. 1 is a top view of a cylindrical, concrete wall having an apparatus of this invention mounted upon its mm;

FIG. 2 is a perspective view of the apparatus from the interior portion of the tank;

FIG. 3 is a side elevation view taken along lines 33 of FIG.. 1;

FIG. 4 is an elevation view, partly in section, taken along lines 4-4 of FIG. 3;

FIG. 5 is a partial view of additional apparatus which may be used with the apparatus of this invention.

Reference numeral refers generally to the cylindrical walls ofa concrete tank. Wall 10 may be integral or may be comprised of a series of panels as depicted by reference numerals 12, 14 and 16. A steel sheath external to the concrete wall is designated by reference numeral 17. Wall 10 has a widened upper rim 18 having a flat surface 20. As shown in FIG. 3, the exterior of the concrete tank is wrapped with a plurality of strands of prestressing wire identified by reference numeral 22. These wires are in tension and cause the concrete wall to be in compression in order to prepare it for its service condition.

Attached to the interior of upper rim 18 of tank wall 10 are a series of beams 30, 32, 34, 36, 38 and 40. These beams may be attached by through bolting of the beams to the exterior of the tank wall. Attached to each of beams 30 through 40 are upright, bracing beams 40, 42, 44, 46, 48 and 50. These beams extend essentially vertically and uprightly and are bolted to beams 30 through 40 by suitable through bolting in the flanges. Attached to-the upper portions of each of bracing beams 40 through 50 and running on a continuous course essentially parallel with the course of concrete wall 10 is a guide rail identified by reference numeral 52. Guide rail 52 is an I beam, as shown more clearly in FIG. 4. A series of cross bracing structures 54 and 56 may be also used to add additional rigidity to the bracing beam structure.

Supported on the upper surface 20 of rim 18 of wall 10 is a scaffoldingidentified generally by reference numeral 60. Scaffolding 60 is comprised of frame members 62, 64, 66, 68 and other structural members, and includes a platform 70 upon which is supported winches 72 and 74. These winches are driven by a motor 76, which is located centrally of the two winches and which has drive axles 78 and 80 associated with it. Also associated with scaffold 60 is at least on horizontal tie bar 82 which extends from the upper portion of scaffold 60 towards bracing beam 52. Pairs of opposed trolley wheels such as 84 and 86 are movably retained in the flanges of guide rail 52. Within scaffold 60 is at least on horizontal axle mounting such as 88 on which is supported axle 90 and vertically oriented rubber tire 92. Rubber tire 92 stands on the upper surface 20 of rim 18 and rolls therealong. Also within scaffold 60 is at least on vertical axle mounting 94 which supports axle 96 and horizontally oriented wheels 98 and 100. These wheels pass around the upper, outer surface of concrete wall 10 and act as guides for the scaffolding. The scaffolding is moved around the periphery of the tank by means .of motive power delivered to axle 90 and wheel 92 by means of a motor, not sown, which shown, be mounted at any suitable locations and connected by suitable gears to axle 90. As shown in FIG. 3, several wheels may be used to support the scaffold on the top rim of the concrete tank. In FIG. 3 such wheels are identified by reference numerals 92, 92a, 92b and 92c".

A work station is supported by means of cables 122 and 124 from winches 72 and 74 respectively. Cables 122 and 124 are fixedly attached to mountings 126 and 128 respectively which are located at a lower point in scaffolding 60 then winches 72 and 74. The cables pass downwardly through blocks 130 and 132 retained on brackets connected to work station 120 and thence pass upwardly to winches 72 and 74. Work station 120 may thus be raised or lowered to any position on the surface of the tank by winding on or paying off cable from the winches. The wheels are preferably provided on the sides of work station 120 and are identified by reference numerals 134, 136, 138 and 140. These wheels are suitably mounted in axle mountings and permit the work station to be moved around the periphery of the tank. In work station 134 is a wire winding apparatus of a type known for winding wire around the exterior of the tank.

FIG. 5 shows a second work station supported by a movable trolley designated by reference numeral which is supportedfrom a continuous plate 152 attached to the bottoms of bracing beams 40 through 50. A suitable pulley system such as that designated by reference numeral 154 may be provided to raise or lower work station 156. As shown, any wire wrapping proceeding on the exterior of the tank does not effect work proceeding on the interior of the tank by means of the apparatus shown in FIG. 5.

What is claimed is:

1. An apparatus for wrapping prestressing steel wire around the outer surface of a concrete tank having a continuous vertical wall including the elements of:

a. a plurality of vertical steel bracing beams attached to the upper part of the inside surface of said concrete wall and extending above said wall, said beams having an I beam guide rail attached to the outer faces thereof and positioned essentially parallel to the course of said wall;

b. a steel scaffold comprised of frame members, movable along the top of said wall and including 1. steel rollers, attached to a said frame member, movable retained on the flanges of said I beam guide rail,

2. a rubber wheel, vertically mounted on an axle mounting in said scaffold, positioned to roll along the top of said wall and including a motor to drive said wheel and scaffold along the top of said wall,

3. a second wheel mounted horizontally in an axle mounting in said scaffold positioned to roll along the upper outer surface of said wall, and

ratus and thence upwardly to said winch.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION.

Patent No. 3,353,277 Dated December 10, 1974 Inventor(s) Billy ROSS Bush It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Col. 5, line 6 Claim 1) change .movable. to

- movably Signed end-sealed this 11th, day of March 1975.

(SEAL) Attest:

r C. MARSHALL DANN RUTH C MASON Commissioner of Patents Attesting Officer and Trademarks 

1. An apparatus for wrapping prestressing steel wire around the outer surface of a concrete tank having a continuous vertical wall including the elements of: a. a plurality of vertical steel bracing beams attached to the upper part of the inside surface of said concrete wall and extending above said wall, said beams having an I beam guide rail attached to the outer faces thereof and positioned essentially parallel to the course of said wall; b. a steel scaffold comprised of frame members, movable along the top of said wall and including
 1. steel rollers, attached to a said frame member, movable retained on the flanges of said I beam guide rail,
 2. a rubber wheel, vertically mounted on an axle mounting in said scaffold, positioned to roll along the top of said wall and including a motor to drive said wheel and scaffold along the top of said wall,
 3. a second wheel mounted horizontally in an axle mounting in said scaffold positioned to roll along the upper outer surface of said wall, and
 4. a support platform having a winch thereupon for raising and lowering an apparatus for winding prestressing Wire, under tension, around said walls; and c. an apparatus for winding prestressing wire, under tension, around said wall, said apparatus being supported from said support platform by a cable associated with said winch.
 2. a rubber wheel, vertically mounted on an axle mounting in said scaffold, positioned to roll along the top of said wall and including a motor to drive said wheel and scaffold along the top of said wall,
 2. An apparatus as recited in claim 1 wherein said cable is fixedly attached to said scaffold below said support platform and passes thence downwardly through a support block associated with said wire winding apparatus and thence upwardly to said winch.
 3. a second wheel mounted horizontally in an axle mounting in said scaffold positioned to roll along the upper outer surface of said wall, and
 4. a support platform having a winch thereupon for raising and lowering an apparatus for winding prestressing Wire, under tension, around said walls; and c. an apparatus for winding prestressing wire, under tension, around said wall, said apparatus being supported from said support platform by a cable associated with said winch. 